1. Field of the Invention
The present invention relates to a pneumatic tire comprising a self-sealing function, to be more specific, a pneumatic tire provided with an adhesive sealant on the inner surface of the tire.
2. Detailed Description of the Prior Art
Conventionally, as measures against a flat tire when a car treads on a nail or the like during running, the following methods have been proposed, such as (1) use of a run-flat tire in which a rigid member is pre-inserted, (2) stopping up the hole by injecting a liquid repair agent into the tire from an air valve when getting a flat tire, (3) pre-lamination of an adhesive sealant on the inner surface of the tire at the time of manufacturing it.
However, the method (1) of using the run-flat tire has the problems that it is increased in weight due to the rigid material, and riding comfort is also damaged. The method (2) of injecting a repair liquid has a less problem about the increase in weight of the tire than the method (1). However, there is the other problem that the driver must come out of the car for performing the injection work when the tire gets punctured.
Compared with the methods (1), (2), the method (3) has advantages that the method has less problem of the increase in weight than the method (1), and the tire is self-sealed without performing the injection work by a human being at the time of getting a flat tire.
However, although the method (3) is more advantageous than the methods (1) and (2), the adhesive sealant needs to be disposed on the inner surface of the tire to a certain extent in thickness, therefore, the increase in weight cannot be avoided compared with a normal tire, and this results in increasing a fuel consumption of a car.
Moreover, since the adhesive sealant is exposed on the inner surface of the tire in the method (3), the workability is bad because the adhesive sealant sticks to the hands or the like when mounting or dismounting the tire on/from a vehicle.